Combines for harvesting grain crops and the like generally include a header of very substantial width, such as of the order of about twenty feet or more, said header including cutting mechanism to separate the grain crop from the lower rooted portions thereof, the cut crop material then being converged toward the center of the header by rotatable auger means having opposite end portions spiralling in reverse directions to each other, the converged crop material then being delivered to the lower, inlet end of an elevator comprising an endless flexible flight, such as transversely extending bars mounted upon a series of endless chains or belts, for movement within an enclosing housing or casing which extends rearwardly and upwardly from the inlet end thereof and to elevate the crop material for discharge to feeding augers adjacent the inlet ends of threshing and separating rotors in the combine.
Particularly when harvesting short green damp crop material or short dry crop material having low structural strength, it has been found that backfeeding of the crop material to the header occurs over the top beater profile when a beater feeder type header is associated with a combine and, when a conventional elevator flight is employed with the combine, in which endless chains and transverse slats comprise the elevating flight means, backfeeding of the crop material under the upper sides of the elevator housing or casing occurs. This problem has been a source of difficulty in harvesting crops of the aforementioned types by a combine for substantial periods of time and although various attempts have been made to obviate the difficulty, none of these have solved the problem of backfeeding to the degree which has been made possible by the present invention.
The backfeeding problem can be caused, for example, by material accumulating in the dead spaces adjacent opposite sides of the housing of the elevator and is retained therealong on the feed ramp comprising the bottom wall of the elevator housing. The material accumulating in said dead spaces at the upper end of the elevator housing cannot be reached by the radial path of the feeding augers of the threshing and sepatating rotors.